Attachment to abtiitcial legs



UNITED STATES PATENT FID..

OLIVER DAVID IVILGOX, OF ELMIRA, NEW YORK.

ATTACHMENT 'IO ARTIFICIAL LEGS.

Specification of Letters Patent No. 21,289, dated August 24, `1858.

. To all w/wm t may concern:

Be it known that I, OLIVER DAvm WILCOX, M. D., of Elmira, in the countyof Chemung and State of New York, have invented a new and usefulImprovement in Artificial Legs; and I do hereby declare that thefollowing is a. full, clear, and exact description of the same,reference being had to the accompanying drawings, making part of thisspecification, in which- Figures 1, and 2, are longitudinal sections ofan artical leg with my improvements.

Similar letters of reference indicate like parts in the two figures.

This invention consists, in providing for the adjustment of thesackwhich forms part of the subject matter of Letters Patent granted to meSepteSOth, 1856, to adapt it to the condition of the stump, by means ofstraps and buckles applied substantially as hereinafter described.

To enable others skilled in the art to apply my invention, I willproceed to describe its construction and operation.

A, is the thigh piece; B, the leg, and C, the foot, all made o-f wood,hollow and as light as possible. These may be fitted t0- gether withmortises and tenons or with flange joints, in the same manner as inartificial limbs heretofore used.

D, is a short lever of the rst order, having one arm secured rigidly byscrews a, a, or otherwise, to the thigh piece. This lever passes througha slot Z in the top of the leg which is hollow, and has for its fulcrumthe knee-joint pin b. E is another short lever of the irstorder, havingone arm secured rigidly to the foot by being driven tightly thereinto orby other means, having for its fulcruin the ankle-joint pin c, andhaving its other arm extended upward into the leg.

F, is a lever of the first order, of nearly the full length of the legB, arranged within the leg, having for its fulcrum a pin (l, which isstationary within the leg, and having its lower arm somewhat shorterthan the upper one. The upper arm of this lever F is connected with thelower arm of the lever D, by a link c, which makes as nearly as possiblea rectangular connection between said levers. The lower arm of the saidlever F, is forked to receive a small sliding block g, which is pivotedto it by a pin n, and which is fitted to slide in a slot in the upperpart of the lever E. j l

j, is a block of hard wood secured in the front of the slot Z, in thetop of the leg and fitted with a piece of india-rubber 7a, which isfaced with a piece of leather. This block cushioned with india-rubberserves as a stop to the upper arm of the lever D, tostiffen the kneejoint when it is straightened.

m, my, are two pieces of leather, one attached to the thigh piece A, andthe other to the leg B, to cover the back of the kneejoint. These piecesare laced together b-y a lace n, which causes such a degree of tensionto be produced on them, as the joint is straightened, as to prevent thelever D coming violently in contact with the stop, j, R.

Gr, is a spring applied within the foot and secured thereto in such amanner that the lower part of the front of the leg will be caused topress upon it by the fleXure of the ankle joint, and thus giveelasticity to said joint in stepping.

The operation of the levers D, E, F, is as follows As the knee is flexedby moving Y it forward in walking, the lower and shorter arm of thelever D by means of its link connection e, throws forward the upper armof the lever F, and throws back the lower end of the latter, which byits slot and slide connection with the lever E, causes the foot to movefrom the ankle oint and the toe to be elevated relatively to the leg sothat it may clear the ground when the foot is raised therefrom and movedforward. The raising of the toe is continued by the flexure of the kneetill the point of connection of the link e, with the lever D, passes infront of the knee-joint pin It is, however, only in sitting down, andnot in walking, that the flexure is suficient for this; but in walking,the iieXure is suicient to cause the elevation of the front part of thefoot .to such a degree as to cause the spring Gr, to be considerablycompressed by the lower part of the leg; and when the foot is raisedfrom the ground, the force of said spring is exerted in throwing downthe foot and transmitted from the foot through the levers E and F, tothrow the foot and leg forward from theknee-joint.V

Though before the foot is brought to the ground the spring Gr isrelieved, the continued forward motion of the leg and foot from the kneejoint, produced by the voluntary motion of the wearers thigh causes thelevers D, F, E, to operate in a manner the reverse of what they didduring the act of iexing the knee, and thus to move the toe downward toa position relatively to the leg to come at to any ordinary surface ofground when it is set down. This connection of the foot, leg, and thighproduces a very close imitation of the movements of the natural leg.

H, is the sack Which receives the stump of the natural limb. When thisis fixed, some diilculty is found in making it produce an equal pressureon all parts of the stump, which is very necessary to the comfort of thewearer; and again, nearly all stumps continue to shrink so that theysettle down in the socket of the thigh piece A, and consequently thesack requires to be raised from time to time. For this purpose I suspendthe sack from several straps p, p, Which pass l Y O. D. WILCOX.

Vitnesses:

S. C. REYNOLDS, R. KING.

